Landing gear for trailers



Dec. 25, 1945. c. BOHLEN, JR

LANDI-LNG GEAR FOR TRAILERS Filed March l''Jv 1944 Patented Dec. 25,1945 UNITED STATES PATENT -OFFICE LANDINGJGEARFon'rnAILERsohariesn'ohren, Jr., Jenkintown, ra.' nppneation March 17, 1944, serialNo.. 526,873

I `rclaims. (01.,.254-s6i This invention relates to a landing gear fortrailers and, more particularlyjfor that type of trailer, known asasemi-trailer, which undertow is supported in part upon the' towingvehicle or prime mover and which consequently requires auxiliarysupportingk means, or landing gear, when detached: from its primekmover, as when loading; unloading; and during stopovers'.

Heretofore' various forms of landinggear have been provided and' whichhave` variously operated mechanically and hydraulically.l However,

such as have been provided heretoforeV have been open to variouspractical objections in' use;

As is well known, the purpose of the landing gear is to support the endportion of a Semi-type trailerl when separated from its primev mover andto enable disconnection fromand connection to a prime mover- AA landinggeary is ordinarily'put into use` when a trailer is-dropped for loadingor unloading, or at a stopover or terminal point in a system oftransportation.

The landing gears heretofore known are sumciently satisfactory Where agiven trailer is always handledl by the same make and modelA 'primemover and where the landing gear when. in use nds a solid, levelfooting. 1

However, more often than not the footing is yielding and underv theweight of the trailer` the landing gear sinks. Aga-i-n, the si-irfaceAupon which the trailer4 stops is irregular and' the'landing gear footsona rise or in a depression. Still again, prime movers differ in theheight oftheir trailer supports, or coupling devices'.

Under the above conditions the landing gears heretofore known arewanting in range and power and hence are variously objectionable; Thus,by way of example, where the landing gear sinks in the surface uponwhich it rests, diiliculty is found 1n raising the trailer, especiallywhen loaded, sufciently to enable the prime mover to get into connectingposition. Again, when the trailer supportsl of a prime mover picking upthe trailer ishigher than the support of ther prime mover which droppedthe trailer, diiiiculty is presented ini raising the trailer to-eiectconnection withA the prime. mover; and when the landing gear initiallyfootsin a depression, diiculty occurs indisconnectingf the primemover. f

Now in accordance with this invention' there is prov1ded a landing gearso constructedY as to be readily manipulated within a wide range for theraming. or lowering of the end of a semi-trailer type trailer supportedby it to place the trailer for connection or disconnection to or from aprime Having now indicated, in a general way, the nature and purpose ofthis' invention, I will proceed to a detailed description of a preferredem,- bodim'ent thereofwith reference to the accompanying. drawing in.which the single ligure' is a side view of a landing gear embodying thisinvention, shown in association with a trailer which issuliciently'indicated. l

f In the drawing I indicates a frame upon which the forward end of atrailerbody 2jis mounted. The rear end of the trailer body will hesupported in any usual manner, as throughr springs mounted on an axlecarrying'wheels, not shown. Beneath'. the forwardVV end of the frame Iis the usual plate 3 and coupling member 4, for the sup'- port andconnection of the trailer to a prime mover, a rear Wheel of which isindicated at 5.

The. landing: gear structure shown* comprises a hydraulic-:cylinder 6,mounted in a bracket' 'l secured to Vframe I, and within whichl is apiston or ram 8*'. The upper end of the cylinder is connected by a' pipe9 to a fluid pressure' pump located' in a casing I'Il-, bolted totheframe IQand including a supply of` Huid, which, for example, may bewater, brake fluid, an oil, orthe like. A handle II extends fronrthecasing for operating the pressure pump to create pressure in thecylindex' 6 onthe upper end of the piston 8, any

usual provision being made, as by a valve, forY release vof the pressurein cylinder 5 back to the supply of uid, when desired.

In contact with, but not secured to, the lower end of the piston 8 is aheaded end of a shaft I2', which is embracedAA by a bracket 'I,depending. from bracket l.. The rod I2 is prevented from dropping awayfrom bracket 1' by its headed end and its upward movement with, respect,to bracket 'I' is limited by an annular ilange I3,4

Pivoted to the lower endof. rod I2., throughthe medium of a pin` I 4, isa leg I5. on. the lower end of which is. mounted, through the medium ofva sleeve I5', a small wheel I6, which acts.v as a. foot. Carried by andlaterally of leg I5,A adjacent` to the pivot I4, is a segmental shoe II.

The leg I5 is pivotally connected to a back bracepla, which in turn ispivotally connected to anut ISgthreaded onlv a horizontal screwA 20,withina casing 2l', secured' to frame t. A handley 22 is' provided forthe` rotation of the screw 20, through the medium of gearing (not shown)carried by frame I, to effectY travel of the. nut. hack and forth on thescrew.

It will be understood that a landing gear device as illustrated anddescribed may be provided on each side of a trailer for independent orcombined operation.

In the operation of the device, for the support of a trailer whendisconnected from its prime mover, the weight ofthe trailer will betaken by the leg I5, rod I2 and piston or ram 8, as shown in full linesin the drawing, it being noted that the piston or ram 8, in extensionpart way out of the cylinder B, will be backed by fluid under pressurein the cylinder 6. The leg I5 will be prevented from breaking on itspivotal connection with rod I2 by the back brace I8, which is held bynut I9.

If now it is desired to raise the trailer, such may be accomplished withease by merely operating the fluid pump by manipulating handle Il toforce more fluid into cylinder 6 and eilect further outward extension ofpiston 8. And when it is desired to lower the trailer, it is onlynecessary to release iiuid from the cylinder 6 to permit retraction ofthe piston 8 into the cylinder 4under the load of the trailer.

When the trailer is coupled to a prime mover for towing, the pressure isreleased from the cylinder 6 and the leg I5 and wheel I6 are drawn up tothe traveling position shown in dotted lines in the drawing by therotation, through the medium of handle 22, of screw 20, and consequenttravel of nut I9, which as shown is connected to leg I5 by back braceI8.

As the leg I5 is drawn up into traveling position, the segmental shoeI'I moves to a downwardly facing position, as shown in dotted lines inthe drawing, in which Vposition it will strike the ground and preventdamage to the trailer body, or its contents should'the trailer becomedetached from its prime mover in transit. The leg I5 will be preventedfrom dropping away from bracket 'I' by the headed end on rod I2.

As will, it is now believed, be obvious, when a trailer is to bedisconnected from its prime mover, the leg I5 will be lowered tosupporting position by rotation of screw 20 and fluid then pumped intocylinder 6 to bring the wheel 8 to a bearing' and raise the trailer tofree the prime mover.

Should the wheel sink into the surface upon which it bears, or should itbe desired to connect the trailer to a new prime mover having a highertrailer support than that from which it was disconnected, the trailermay be readily raised by y the application of pressure to cylinder 6 toaccommodate it to the prime mover; and the trailer may be equallyreadily lowered to support by a prime mover by release of fluid from thecylinder 6.

It will be noted that the landing gear described is readily accommodatedto irregular surfaces, upon which it may bear with respect to oppositesides of the trailer.

Needless to say, various modifications in the structure described abovein detail may be made without departing fromV this invention or thescope of theclaims appended hereto. l

What I claim and desire to protect by Letters Patent is:

1. In a landing gear for trailers, in combination, a cylinder, a pistonin said cylinder, means for supplying fluid under pressure to saidcylinder, a rod slidably supported in line with said piston and adaptedfor end contact therewith but free to move out of contact therewith, aleg pivotally connected to said rod and means. OI mOV- ing said legabout its pivotal connection with said rod.

2. In a landing gear for trailers, in combination, a cylinder, a pistonin said cylinder, means for supplying iiuid under pressure to saidcylinder, a rod slidably supported in line with said piston and adaptedfor end contact therewith but free to move out of contact therewith, aleg pivotally connected to said rod, means for moving said leg about itspivotal connection with said rod and a ground bearing member carried bysaid leg.

3. In a landing gear for trailers, in combination, a cylinder, a pistonin said cylinder, means for supplying uid under pressure to saidcylinder, a rod slidably supported in line with said piston and adaptedfor end contact therewith, a leg pivotally connected tosaid rod, meansfor moving said leg about its pivotal connection with said rod and asegmental shoe carried by and laterally of said leg adjacent its pivotalconnection with said rod.

4. In a landing gear for trailers, in combina tion, a verticallyextending cylinder, a piston in said cylinder, means for supplying fluidunder pressure to the top of said cylinder, a rod mounted for verticalmovement in line with said piston and adapted for end contact therewithbut free to move out of contact therewith, means to limit the verticalmovement of said rod, a leg pivotally connected at one end to the end ofsaid rod remote from said piston and means for moving said leg about itspivotal connection with said rod.

5. In a landing gear for trailers, in combination, a verticallyextending cylinder, a piston in said cylinder, means for supplying fluidunder pressure to the top of said cylinder, a rod mounted for verticalmovement in line with said piston and adapted for end contact therewithbut free to move out of contact therewith, means to limit the verticalmovement of said rod, a leg pivotally connected at one end to the end ofsaid rod remote from said piston, a horizontally eX- tending screw, anut threaded on said screw, a back brace pivotally connected vto saidnut and leg and means to rotate said screw.

6. In a landing gear for trailers, in combination, a vertical extendingcylinder, a piston in said cylinder, means for lsupplying uid underpressure to the top of said cylinder, a bracket extending below saidcylinder, a rod having a headed end slidably supported by said bracketand adapted to bear on said piston, a leg pivoted adjacent one end tosaid rod and means t5 rotate said leg about its pivotal connection withsaid leg. f

7. In a, landinggear for trailers, in combination, a verticallyextending cylinder, a piston in said cylinder, means for supplying iluidunder pressure to the top of said cylinder, a rod mounted for verticalmovement in line with said piston and adapted for end contact therewith,means to limit the vertical movement of said rod, a leg pivotallyconnected at one end to the end of said rod remote from said piston,means for moving said leg about its pivotal connection with said rod,bearing means carried by the free end of said leg and a segmental shoecarried by and laterally of said leg adjacent its pivotal connectionwith said rod.

CHARLES BOI-ILEN, Ja.V

